Comprehensive Investigation of Overmodulation Methods With Low Current Distortion for Dual Three-Phase Motor Drives

The overmodulation (OVM) technique is commonly adopted to fully improve the dc-bus utilization. In this article, a comprehensive investigation of different OVM methods for the dual three-phase motor drive is conducted in terms of current distortion. To provide the benchmark of the actual minimum current distortion (MCD), the MCD OVM method is proposed based on the space vector concept, which leads to an optimization problem with reduced computational complexity. Moreover, the well-known three-phase OVM methods are extended to the dual three-phase motor drive for more choices in the OVM range. A thorough performance comparison of the OVM methods provides meaningful information for improved OVM operation. Simulation and experimental results on a 7.5-kW dual three-phase induction motor drive are given to confirm the correctness of the theoretical analysis and the validity of the proposed MCD OVM.